Table 2. Optimization of the reaction conditions.

Entry	Catalyst	Base	Time	Conversion a	Yield b
1 c , d	1	Cs2CO3	2 h	>95%	55%
2 d	2	Cs2CO3	2 h	50%	20%
3 d	3	Cs2CO3	2 h	90%	5%
4	4a	Cs2CO3	2 h–6 h	60%	50%
5	4c	Cs2CO3	2 h	>95%	70%
6	4c	K2CO3	2 h	>95%	75%
7	4c	K2CO3	1 h	>95%	80%
8	4d	K2CO3	1 h	>95%	75%
9	4b	K2CO3	1 h	>95%	75%
10 e	4c	K2CO3	1 h	>95%	70%
11 f	4c	K2CO3	1 h	>95%	80%
12	4c	K2CO3	0.5 h	>95%	80%
13	—	K2CO3	1 h	NR	NR
14	4c	—	1 h	<10%	5%
15 g	4c	K2CO3	1 h	NR	NR

^aReaction conditions: using 0.1 mmol 12a (1 equiv.), 0.2 mmol 5a (2.0 equiv.), 5 mol% 1–4 (0.05 equiv.) in DCE (2.0 mL) for 2 h at RT. The conversion of 12a by NMR is given. NR = no reactivity.

^bNMR yield using dibromomethane as internal standard.

^cUsing 1 mol% of 1.

^dUsing 1.0 equiv. of base.

^eUsing 1.5 equiv. of 5a.

^fUsing 3.0 mol% of organic dye 4c.

^gWithout irradiation.